Internet Area WG J. Touch
Internet Draft USC/ISI
Updates: 791,1122,2003 May 30, 2012
Intended status: Proposed Standard
Expires: November 2012
Updated Specification of the IPv4 ID Field
draft-ietf-intarea-ipv4-id-update-05.txt
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Abstract
The IPv4 Identification (ID) field enables fragmentation and
reassembly, and as currently specified is required to be unique
within the maximum lifetime for all datagrams with a given
source/destination/protocol tuple. If enforced, this uniqueness
requirement would limit all connections to 6.4 Mbps. Because
individual connections commonly exceed this speed, it is clear that
existing systems violate the current specification. This document
updates the specification of the IPv4 ID field in RFC791, RFC1122,
and RFC2003 to more closely reflect current practice and to more
closely match IPv6 so that the field's value is defined only when a
datagram is actually fragmented. It also discusses the impact of
these changes on how datagrams are used.
Table of Contents
1. Introduction...................................................3
2. Conventions used in this document..............................3
3. The IPv4 ID Field..............................................4
4. Uses of the IPv4 ID Field......................................4
5. Background on IPv4 ID Reassembly Issues........................5
6. Updates to the IPv4 ID Specification...........................6
6.1. IPv4 ID Used Only for Fragmentation.......................7
6.2. Encourage Safe IPv4 ID Use................................8
6.3. IPv4 ID Requirements That Persist.........................8
7. Impact on Datagram Use.........................................9
8. Updates to Existing Standards..................................9
8.1. Updates to RFC 791.......................................10
8.2. Updates to RFC 1122......................................10
8.3. Updates to RFC 2003......................................11
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